There is a demand for thoroughly mixed or ultrafine, stable mixtures in various fields, such as the production of cosmetics, foods, and especially fuels and combustibles.
Numerous emulsifiers or emulsionizers which produce an oil-in water type emulsion are already known. Such an emulsion has a certain degree of fineness and is only minimally stable, enough to satisfy its intended purpose.
Many emulsifiers are merely improved homogenizers capable of producing only a low quality, unstable, coarse emulsion.
However, emulsifiers do exist are which capable of producing an emulsion with adequate characteristics and qualities for a particular purpose.
Movable disc emulsifiers for immiscible liquids are known in the art, as described in Patent Nos. FR 2 461 515 filed Jul. 27, 1979 by Robert Guerin and FR 2 731 504 by Societe MEROBEL.
In the first invention of Robert Guerin, the emulsifier is formed by stacking annular units stored in a tube sealed at each end by a coupling piece. These annular pieces can slide along a median longitudinal axis and they are separated from one another by a central lateral tubular extension allowing them to interlock. Each annular element has two types of peripheral notches disposed so that they form baffled passageways between one annular element and the next. The stack forms a block maintained in flexible equilibrium at a distance from the tube extremities by helicoidal springs which simultaneously provide cohesion to the unit. The fluid arrives through the hollow extremities of the median longitudinal axis on which the annular elements are mounted. The liquid mixture travels along the annular space occupied by the annular elements and leaves the tube in an emulsified state. Thus, the entire block is subjected to oscillation caused by the pulsating effects of cavitation.
Since the liquid passes through only the notches in this unit, the emulsifier loses considerable capacity and the emulsifying effect is limited to what can occur during passage through the baffles.
Additionally, the configuration of this device and the stacked arrangement cause the annular elements to become blocked fairly quickly.
Furthermore, it is not possible to produce an ultrafine emulsion, as there is no high frequency fluid shearing.
The main features of the second invention derive from the first invention. The stack consists of a succession of perforated cylindrical plates and interposed layers of passageways with bi-conical tapered portions separated from one another by empty areas, with the unit forming a block fitted within a tubular body. The passageways between successive plates and layers are laterally offset so as to form baffles.
Here again, the baffle structure prevents achieving an ultrafine emulsion. The baffle structure forming a compact stack either will not allow the plates and layers to vibrate at all, or prevents them from vibrating enough to attain the amplitudes required to make the even higher frequencies effective. Such high frequency vibrations combine with the shearing phenomenon to produce an ultrafine emulsion.
Also known in the art is Russian Patent No. SU 1 678 426 filed Oct. 10, 1989 relating to a liquid cavitation emulsifier.
This mixing device consists of masses that are movable along a median longitudinal axis, separated from one another by a spring. These masses are solid and thick. They can only be displaced enough to oscillate at a low speed, thus preventing auto-resonance at a high enough frequency to create an emulsion, and certainly not an ultrafine emulsion such as the emulsion which is the object of the present invention.
The goal of the invention is to produce an ultrafine emulsion from two immiscible liquids while using the smallest amount of energy possible.
With the method of the present invention, it is possible to achieve thoroughly mixed emulsions which extend the limits of stability and finesse, and to attain ultracolloidal quality which is immune from substantial physical modifications over a period of several weeks or even several months, while consuming vastly reduced amounts of energy.
The applications vary depending upon the initial product. This may be a fatty food product, and the invention may produce fatty food emulsions for light cuisine such as margarine or shortening. Or it may consist of fatty emulsions used in the composition of beauty products or lotions.
In the domain of fuels, it is possible to envision a diesel vehicle operating with an emulsion of water and gasoline as a fuel. The use of variable amounts of water over a broad range would maintain essentially the same level of performance. But more importantly, the quality of combustion and reduction in engine emissions and oily byproducts would contribute significantly to pollution control efforts.
The same is true with hydrocarbon fuels such as light fuel oil, heavy fuel oil, and the like.
An ultracolloidal emulsion produces cleaner combustion in heating fuel, which is self-cleaning and economical in terms of energy costs.